The present invention relates to an apparatus to supply articles in succession to a printing station, and more particularly to such an apparatus to provide an orderly conveyance of articles from a chute onto a conveyor for delivery thereby to a printing station.
While not so limited, the present invention is particularly useful for delivering a succession of bottle caps to a printing station where the top face surface of each cap moves into contact with an inked image carried by a transfer roll. In this type of printing process, the bottle caps, typically made of plastic, are supplied and removed from a printing operation in bulk containers. It is necessary, therefore, to orientate the bottle caps so that their surfaces intended for printing are arranged for contact with the ink transfer roll. One form of sorting apparatus is a vibratory container having an open top to receive a supply of bottle caps and an opening in the side wall to discharge an orientated supply of bottle caps. The bottle caps orientated by the sorting apparatus must be moved in a synchronous relation with the peripheral surface speed of the transfer roll. The movement of the caps must be in a timed relation to pass into contact with one or more inked patterns of indicia on the transfer roll to insure transfer of the ink onto each cap at the desired printing site.
Because of the size and weight of the article, a roller-chain type conveyor is suitable to transport articles, such as bottle caps, for contact with an ink transfer roll. However, there remains the problem of loading the articles from the sorting device onto the conveyor. The loading operation must be accurate and effective without stoppages to the flow of articles to the ink transfer roll. A mechanical transfer mechanism might achieve the intended result but is undesirable because mechanical failure and malfunctions inherently occur causing a disruption to the entire printing process. However, the loading operation must accommodate article-pretreating operations for the printing process. Specifically, the surface of a plastic bottle cap to receive liquefied thermoplastic ink is usually flame-treated to enhance transfer of such ink.